They've been censored on every other platform for years. Imagine you're a kid in highschool, experimenting with the wild world of internet chat, and naively express an attitude in that general direction - and promptly get banned or worse, shadow banned. That hurts. And it gets a reaction - which is, whatever the censorship jerks hate is what they want to rub in their face. So it intensifies...

TBH, the damage done by censorship is so great at this point that I think a round two of Nazis is inevitable. There's probably more Nazis now than there were when they had control of a country. All because statist control freaks just had to wield the ban hammer on just about everything.